The invention relates to a device for supplying electricity to an agricultural utility vehicle and/or an attachment which can be coupled to the utility vehicle.
Agricultural utility vehicles such as, for example, field choppers, self-propelling spraying devices and tractors are known from the prior art. A tractor is a versatile utility vehicle since different attachments can be coupled to a tractor. Ploughs, harrows, grubbers, seeders, spraying machines, rotary mowers and round balers are usually coupled to a tractor. Accordingly a tractor with a respectively coupled attachment carries out a wide variety of agricultural working functions. This makes it also necessary for the tractor to actuate the respective attachment in a corresponding way if the agricultural working function which is carried out with the attachment is carried out with an actuator, a tool or with a motor.
Attachments are known whose actuators or tools are driven mechanically, wherein mechanical driving power is transmitted to the attachment from a power take-off shaft provided on the tractor. An example of such an attachment is a round baler. Furthermore, attachments are known which are driven hydraulically. For this purpose, hydraulic quick-release couplings are provided on the tractor and are connected to hoses of the attachment. Such an attachment is, for example, a front loader or a towed spraying machine. In the case of the front loader, the boom is controlled and activated hydraulically. In the case of the towed spraying machine, the linkage is adjusted hydraulically.
Both the mechanical and the hydraulic transmission of power between the utility vehicle and the attachment entail problems in terms of actuation. It is therefore necessary, inter alia, for the internal combustion engine of the utility vehicle to be operated at a certain rotational speed and/or for the gear mechanism to have a certain, predefined transmission ratio to enable the attachment which is actuated via the power take-off shaft to be operated correctly. This may result in a poor level of efficiency of the tractor-trailer combination composed of the utility vehicle and attachment.
Attachments are known which have electrical loads. These are electric motors and/or fans of a relatively low power class. Furthermore, lighting devices and/or solenoids can be operated electrically as actuator drives. Hitherto they have been supplied by the vehicle on-board electrical system of the utility vehicle. Electrical energy which is necessary for this is generated by the conventional dynamo of the utility vehicle. Hitherto, attachments with electrical loads which have a relatively high power drain for carrying out an agricultural working function have not been used.
The problem to be solved then is that of providing a utility vehicle with an electric power supply sufficient for providing sufficient electric power for driving relatively large electrical loads of an attachment coupled to the vehicle.